Mexico said Tuesday that it had chosen a U.S.-based Mexican academic as its new ambassador to Washington, filling a key diplomatic post left vacant for five months.

Mexico's Foreign Relations Department said the new ambassador would be Miguel Basanez, who is currently an adjunct professor at the Fletcher School of Law and Diplomacy at Tufts University in Medford, Massachusetts.

The ambassadorship to Mexico's most important trade and investment partner had been vacant since former Ambassador Eduardo Medina Mora was nominated to Mexico's Supreme Court in March.

Analysts had questioned why Mexico left the post vacant so long. About 11.4 million Mexican-born people live in the United States, and about 1 million U.S. citizens live in Mexico, according to the department.

The department said Basanez plans to "promote the empowerment of the Mexican community'' in the United States.

Basanez is an expert on opinion polling who received much of his postgraduate education at British universities.

According to his Fletcher School academic profile, Basanez "assisted in the expansion of democracy in Mexico through the introduction of opinion polling for elections in 1985.'' Until then, opinion polls were little used and seldom trusted, and the country had been ruled for over 55 years by the Institutional Revolutionary Party. The PRI, as the party is known, lost the presidency in 2000 and regained it in 2012.

Basanez also worked for PRI governments before going to the United States to continue his academic career.